Control mechanism for stuffer crimper

ABSTRACT

A stuffer crimper including a crimping chamber and a cooling chamber in the form of a plurality of spaced rods arranged to confine the crimped core. A choke member in the form of hinged fingers extend between the rods and exert pressure on the sides of the core for compacting the same and retarding the advance thereof. A feeler member engages the end of the core to control the rate of feed. The feed rolls are driven through a stepped pulley.

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487,711 426,833 France R E w N r R c R E F F U T S R 0 F. the 1F m 8 m o Er D Ln m m 0C C8 M U ABSTRACT: A stuffer crimper including a crimping chamber 2 1 l l 7 056 m1 8 2 mh Q w m xm IF 1] 0 55 [1 and a cooling chamber in the form ofa p1ura1ity of spaced rods arranged to confine the crimped core. A choke member in the References Cited form of hinged fingers extend between the rods and exert pressure on the sides of the core for compacting the same and retarding the advance thereof. A feeler member engages the end 19/66 (A) of the core to control the rate of feed. The feed rolls are driven 28/1 6 through a stepped pulley.

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l l l lllllL CONTROL MECHANISM FOR STUFFER CRIMPER This application is a continuation of copending Application Ser. NO. 631,099 filed Apr. 14, 1967 now abandoned which application is a continuation of application Ser. NO. 406,240 filed Oct. 26, 1964 now abandoned.

This invention relates to a method and apparatus for crimping yarn and has for an object to provide a method and apparatus of the above type having novel and improved characteristics.

Another object is to provide a method and apparatus of the above type having novel and improved details of construction and features ofoperation.

Various other objects and advantages will be apparent as the nature ofthe invention is more fully disclosed.

In accordance with one embodiment the invention is shown as applied to a stuffer crimper of the type wherein the yarn is fed between a pair of feed rolls into a confined crimping chamber wherein it is folded over and crimped against the mass of previously crimped yarn held compacted in said chamber.

One feature of the invention includes a preheating zone wherein the yarn is fed overa heated surface while being held under a stretching tension in advance of the feed rolls. The stretching of the filaments serves to orient the molecules and improves the tensile strength of the filaments. At the same timethe heating relaxes the filaments and softens them to an extent such that feeding by the feed rolls and the subsequent crimping in the crimping chamber are facilitated. In a specific embodiment the yarn is stretched between the feed rolls and a stretch roll in advance thereof which are driven at appropriate speeds. The preheater is in the form of an arcuate plate over which the yarn passes in its path-between the stretch roll and the feed rolls.

A further feature of the invention comprises the use of a crimping chamber having an elongated, rectangular cross section, and a traversing guide to traverse the yarn axially of the feed rolls as it is fed thereto so as to cause the yarn to pack the crimping chamber uniformly throughout its entire cross section.

In accordance with another feature of the invention the surface of one of the feed rolls is ground in such a manner as to improve the frictional grip of the feed rolls on the filaments. For this purpose the feed roll is ground by reciprocating a grinding wheel axially across the peripheral surface ofthe feed roll as the feed roll is rotated slowly. In this way a series of microscopic grooves and ridges are formed on the surface of the roll which increase its frictional grip on the filaments. The microscopic grooves, however, do not roughen the surface of the roll to an extent that would cause injury to the fine filaments.

Another feature is an improved cooling zone for the crimped yarn formed by a series of spaced rods which form an extension of the crimping chamber and are so arranged that the core of crimped yarn which is discharged from the crimping chamber passes along and is held confined by the rods as it advances to a discharge point. A choke in the form ofa pair of opposed rake members extends between the rods to engage opposite sides of the core of yarn so as to maintain a predetermined back pressure thereon during a predetermined portion of the cooling stage. The crimped yarn is withdrawn from the cooling zone at a predetermined rate and a feeler is provided to control the rate of the feed rolls in a sense to maintain a predetermined mass of yarn in the cooling zone.

The nature of the invention will be better understood from the following description, taken in connection with the accompanying drawings in which certain specific embodiments have been set forth for purposes of illustration.

In the Drawings:

FIGS. 1 and 1A when joined along the line a-a show a side elevation ofa stuffer crimper embodying the invention;

FIGS. 2 and 2A when joined along the line b-b show a front elevation of the stuffer crimper;

FIGS. 3, 4, and 6 are horizontal sections taken along the lines 3-3, 4-4, 5-5, and 6-6, respectively, of FIG. 1 showing the construction of the parts embodied in the crimping and cooling zones;

FIG. 7 is a sectional detail showing the construction of the dye applicators;

FIG. 8 is a section taken on line 8-8 of FIG. 7; and

FIG. 9 is a detail illustrating a further embodiment of the feed roll drive mechanism.

Referring to the drawings more in detail the invention is shown as embodied in a stuffer crimper comprising a housing 11 having an elongated, vertical bore 12 therein forming a crimping chamber. The chamber is rectangular in horizontal cross section with straight front and backwalls 13 and end walls 14 which are rounded so as to avoid sharp corners which might injure the crimping yarn therein. The housing 11 is enclosed within a block 15 having heating rods 16 disposed therein for maintaining a desired degree of heat in the crimping chamber and extends above the block 15. At its upper end the housing 11 carries a collar 17 in which a series of spaced vertical rods 19 are supported. The rods 19 extend around the periphery of the crimping chamber 12 with their inner surfaces tangent thereto so that the rods form an extension of the chamber. The upper ends of the rods 19 are held in a horizontal wall 20 so as to form a cooling cage for the crimped filaments as the core 21 of crimped filaments advances upwardly along the rods.

A pair of choke members in the form of opposed rakes are disposed to maintain a predetermined back pressure on the core 21 of crimped filaments in the cooling zone. These members each comprises a set of curved fingers 23 carried on a pivotal shaft 25 which is journaled in a frame 26. The frame 26 includes end members having bosses 27 depending from the frame which are adjustably supported on rods 31 secured in the collar 17. Each shaft 25 carries a rod 32 having a weight 33 thereon which is adjustable along the rod 32 for controlling the pressure exerted by the fingers 23 against the core of crimped filaments in the cooling cage. The fingers extend between the rods 19 into contact with the opposite sides of the core 21. The point of contact of the fingers 23 with the core 21.and the consequent length of core held compacted in the cooling zone is controlled by adjusting the bosses 27 along their supporting rods 31.

In the form shown the fingers 23 are provided with internal passages 35 communicating with an axial passage 36 in the shaft 25 and having discharge openings 37 at or about the point of contact with the sides of the core. A dye or other treating liquid may be supplied to the axial passage 36 by a flexible tube 38.

The'dye or other treating liquid is caused to impregnate the filaments in the cooling zone to a degree which is determined by the rates of feed of the core 21 and of the liquid and the density of the core. Additional treating liquid may be applied to the core above the compacting fingers 23 where the core is less highly compacted and the liquid can penetrate more freely by a series of nozzles 41 held in a bracket 42 and terminating in felt pads 43 or the like in contact with the sides of the core 21. The nozzles 41 may be supplied with treating liquid by supply ducts 44.

The crimped yarn 50 is withdrawn from the top of the core 21 through a weighted bar tension gate 51, over a guide bar 49 to a roll 52, thence to a roll 50 mounted on a bracket 57 and to a winder, not shown, which may be of the constant speed type.

For controlling the feed of the core a feeler 60 is positioned to rest lightly on the top of the core 21 and is carried by an arm 61 which forms the control arm of a microswitch 62 mounted on the bracket 42 which is connected to control a feed motor to be described.

A pair of feed rolls and 71 are disposed at the lower end of the crimping chamber 12 in a position to feed the yarn thereto for crimping. The feed roll 70 is mounted on a shaft 72 which is journaled in a bracket 73 and carries a stepped pulley 74 driven by belt 75 from the shaft 76 of a motor 77. Two bifurcated arms 80 actuated by a solenoid 81 are adapted to shift the belt 75 between and larger and smaller diameter steps of the pulley 74 for varying the speed of the feed rolls 70 and 71. The feed roll 71 is mounted on a bracket 82 which is pivoted at 83 and is spring pressed into pressure engagement with the yarn at the bite of the rolls. A set screw 85 which may have a micrometer setting is held in the bracket 82 to form an adjustable stop to limit the minimum clearance between the feed rolls 70. This prevents damaging the filaments by the application of excessive pressure and also prevents the feed rolls from coming into contact with consequent danger of injury to the surfaces of the feed rolls on the absence of any filament in the bite. This is particularly important where one of the feed rolls has a roughened surface.

The feed roll 71 may be driven with the roll 70 by gears, not shown. At least one of the feed rolls, for example roll 70, may be ground transversely. That is, the grinding wheel is reciprocated axially of the peripheral surface of the roll as the roll is slowly rotated. This forms broken microscopic grooves with intervening ridges extending across the peripheral surface of the roll as indicated by lines 86, The grooves are so microscopic in size that. they are barely visible except by reflected light and the surface feels slightly rough to the touch. However, the frictional grip of the rolls on the yarn is increased to an extent such that a lower pressure may be maintained on the filaments as they are fed through the bite of the rolls 70 and 71. Hence the filaments are not distorted or deformed by the feed rolls. This is of particular importance in the case of soft filaments such as preheated acrylics. lt has been found that a roll having peripheral ridges and grooves of a depth of the order of 45-80 microinches is suitable for the above purposes.

The feed rolls 70 and 71 are mounted with their axes paralleled to the long sides 13 of the crimping chamber. A traversing'guide 90 is disposed to feed the yarn 50 to the bite of the rolls. This guide 90 is carried by a forked arm 91 supported to slide on bars 92 having a cam follower 93 reciprocated by a helical groove 94 of a cam roll 95 which is driven by a train of gears 96 from the feed roll shaft 72. The reciprocation of the guide 90 is designed to effect a uniform packing of the yarn across the entire cross-sectional area of the crimping chamber. In certain instances, however, where a nonuniform or spaced effect is desired, the yarn guide 90 may remain stationary in a position to feed the yarn into the center of the crimping chamber. In this case the yarn may become more highly crimped and compacted at the center of the chamber and less highly crimped and compacted at the edges of the chamber so that the different crimp effects are randomly distributed along the yarn.

The yarn 50 is fed around a stretch roll 97 and a guide roll 98 is a succession ofloops 99, thence over the arcuate surface 100 ofa preheater 101 and through the traversing guide 90 to the bite of the feed rolls 70 and 71. The stretch roll 97 is driven by a belt 102 from the driven shaft 72 and the guide roll 98 is driven with the stretch roll 97 by a train of gears 103. The rate of the stretch roll 97 is so related to the rate of the feed rolls 70 and 71 that the yarn is stretched in the preheating zone. The amount of stretch is such that the molecules of the filaments are oriented longitudinally for increasing the tensile strength of the filaments. Although this would tend to impart a harsher feel to the filaments this effect is compensated for by the softening in the preheating stage and the crimping and bulking to which the filaments are later subjected. The microswitch 62 is connected to control the solenoid 81 in a sense to increase or decrease the rate of feed of the filaments in accordance with the position of the top surface of the core with respect to the feeler member 60.

In the embodiment of FIG. 9 a pulley 107 having a hub 108 is pinned to the shaft 72 and is driven by the belt 75. The hub 108 carries the inner race of a ball bearing 109 on which a flywheel 110 is mounted. The ball bearing 109 is packed with a material such as heavy grease which is adapted to provide a friction drag between the shaft 72 and the flywheel 110. The flywheel 110 thus rotates with the shaft 72 and, by its inertia,

retards the deceleration of the shaft 72 when the driving motor is deenergized. The friction drag of the bearing 109 reduces the shock on the shaft 72 when the drive is again energized, thereby smoothing out the cycles of operation of the shaft and of the feed rolls as the drive motor 77 is alternately energized and deenergized by the microswitch 62 as the feeler 60 rises and falls. The action is timed so that the feed rolls do not come to rest during the off portions of the cycle. Either the stepped pulley 74 or the inertia drive prevents the filaments from becoming stationary and overheating on the preheater.

While the fingers 23 maintain the core 21 under the predetermined back pressure in the crimping and cooling zones, the portion of the core above the points of contact of the fingers 23 is free of back pressure except for the pressure exerted by the light feeler member 60. Hence the cooling air can permeate more readily the less highly compacted core in this portion of the cooling zone prior to the yarn being withdrawn under tension.

lclaim:

1. Yarn crimping apparatus comprising means having core contacting surfaces forming confined crimping and cooling zones having substantially the same cross-sectional areas along their entire length along which a core ofcrimped yarn is passed between input and discharge ends, and having a side opening completely through the contacting surface adapted to receive a choke member at a point spaced in advance of said discharge end, feed rolls disposed to feed yarn for crimping into said input end to be folded over and crimped against the core of previously crimped yarn held confined in said crimping zone and to advance said core along said zones to said discharge end, a choke member comprising a pivoted arm extending through said opening into contact with a side of said core at a point spaced from said discharge end and being unrestricted in its pivoting movement by said contacting surface by said core into the plane of said contacting surface to avoid thereby constricting said cross-sectional area, and thus obtaining a more uniform crimp, yieldable means holding said arm in pressure contact with said core for exerting a retarding force thereon adapted to control the back pressure of said core in said crimping zone, means withdrawing the crimped yarn from said discharge end and sensing means disposed to sense the position of the discharge end of said core to be actuated for controlling the level ofsaid discharge end of said core.

2. Apparatus as set forth in claim 1 in which a heating member is disposed to supply heat to a portion of the length of said chamber for heating the crimped yarn therein to a setting temperature and said choke member is disposed at the end of said heating member.

3. Apparatus as set forth in claim 1 in which said yieldable means comprises a weight adapted to hold said arm in pressure engagement with said core.

4. Apparatus as set forth in claim 3 in which said weight is adjustable for varying the pressure of said arm against the core.

5. Apparatus for crimping yarn comprising a crimping chamber having input and discharge ends and means including a feed roll disposed to feed yarn into the input end of said chamber to be folded over and crimped against a core of previously crimped yarn held compacted in said chamber, means driving said feed roll comprising a driving pulley having at least two steps anda continuously driven driving belt in driving engagement with said pulley, and means responsive to variations in the quantity of crimped yarn in said core connected to shift said belt between said steps for varying the speed of said feed roll between two predetermined rates in a sense to maintain said quantity substantially constant.

6. A stuffer crimper comprising a chamber having inlet and discharge ends, feed rolls disposed to feed a yarn into the inlet end of said chamber to be folded over and crimped against the core of previously crimped yarn in said chamber, a cooling cage disposed in alignment with said chamber and adapted to receive the crimped core from said discharge end, said cage comprising a series of rods spaced around the periphery of said chamber at the discharge end thereofwith their inner surfaces forming a continuation of said chamber and adapted to confine said core as it is discharged from said chamber and advances along said rods, a choke member disposed to compress and compact said core at a point in advance of the discharge end thereof for impeding the advance of said core and controlling the back pressure on the core between said choke member and said feed rolls, said choke member comprising spaced pivoted fingers disposed to extend between said rods into engagement with said core into contact with a side of said core, yieldable means holding said fingers in pressure engagement with said core, sensing means spaced beyond said choke member to sense the position ofthe discharge end of said core and to be actuated thereby, means withdrawing the crimped yarn from said core at said discharge end and means responsive to said sensing means to control the relative rate s of feed into and withdrawal from said chamber in a sense to maintain the discharge end ofsaid core at a substantially constant level.

7. Apparatus as set forth in claim 6 in which said fingers are provided with fluid passages having discharge openings positioned to apply a treating liquid to the contacting surface of said core.

8. Apparatus as set forth in claim 6 including a series of nozzles positioned above said fingers in the direction of advance of said core and adapted to apply a treating liquid to the sides of said core in the zone between said fingers and the point of withdrawal of the yarn. 

2. Apparatus as set forth in claim 1 in which a heating member is disposed to supply heat to a portion of the length of said chamber for heating the crimped yarn therein to a setting temperature and said choke member is disposed at the end of said heating member.
 3. Apparatus as set forth in claim 1 in which said yieldable means comprises a weight adapted to hold said arm in pressure engagement with said core.
 4. Apparatus as set forth in claim 3 in which said weight is adjustable for varying the pressure of said arm against the core.
 5. Apparatus for crimping yarn comprising a crimping chamber having input and discharge ends and means including a feed roll disposed to feed yarn into the input end of said chamber to be folded over and crimped against a core of previously crimped yarn held compacted in said chamber, means driving said feed roll comprising a driving pulley having at least two steps and a continuously driven driving belt in driving engagement with said pulley, and means responsive to variations in the quantity of crimped yarn in said core connected to shift said belt between said steps for varying the speed of said feed roll between two predetermined rates in a sense to maintain said quantity substantially constant.
 6. A stuffer crimper comprising a chamber having inlet and discharge ends, feed rolls disposed to feed a yarn into the inlet end of said chamber to be folded over and crimped against the core of previously crimped yarn in said chamber, a cooling cage disposed in alignment with said chamber and adapted to receive the crimped core from said discharge end, said cage comprising a series of rods spaced around the periphery of said chamber at the discharge end thereof with their inner surfaces forming a continuation of said chamber and adapted to confine said core as it is discharged from said chamber and advances along said rods, a choke member disposed to compress and compact said core at a point in advance of the discharge end thereof for impeding the advance of said core and controlling the back pressure on the core between said choke member and said feed rolls, said choke member comprising spaced pivoted fingers disposed to extend between said rods into engagement with said core into contact with a side of said core, yieldable means holding said fingers in pressure engagement with said core, sensing means spaced beyond said choke member to sense the position of the discharge end of said core and to be actuated thereby, means withdrawing the crimped yarn from said core at said discharge end and means responsive to said sensing means to control the relative rate s of feed into and withdrawal from said chamber in a sense to maintain the discharge end of said core at a substantially constant level.
 7. Apparatus as set forth in claim 6 in which said fingers are provided with fluid passages having discharge openings positioned to apply a treating liquid to the contacting surface of said core.
 8. Apparatus as set forth in claim 6 including a series of nozzles positioned above said fingers in the direction of advance of said coRe and adapted to apply a treating liquid to the sides of said core in the zone between said fingers and the point of withdrawal of the yarn. 